1. Field of the Invention
The invention relates to an apparatus for folding in a front face of a pack made of cardboard material coated with plastics material, the front face of which pack when folded in is substantially quadrangular in the plan view and has a transverse sealing seam which can be folded over, having a fold member and a companion fold member which are both driven movably along specific paths of movement by means of at least one lever mechanism and amongst which a conveyer is arranged at a spacing away in the Y-extent, which conveyer moves the packs in the X-extent, wherein the Y-axis is vertical to the X-axis and the zero point of the axes is disposed in the end fold position of the two fold members.
2. Description of the Related Art
As known, packs made of coated cardboard have a substantially tubular main body with front faces at the ends. Usually, the one front face is the lid and the other front face is the bottom. At least one of the two front faces, e.g. the bottom, is substantially quadrangular in the plan view in the folded in condition of known packs. With other packs, the lid is provided with a so-called gable type closure which is also quadrangular in the plan view. It is also possible to fold over the gable closure so that it is flat and so that this front face on the lid side is vertical to the tube walls. With this invention whether the front face is a lid or a bottom is immaterial.
A folding in apparatus is also known similar to the kind mentioned in the introduction, wherein the front face is a lid. The web of material of the pack which is to be closed is circular, and there are various fold- and weld stations along the circular web. Each fold station has a fold member and a companion fold member which both travel about axes on part circular paths, these axes being disposed approximately in the radial extent relative to the revolving assembly. It has been shown that the Front walls which have to be folded must be pre-folded first of all, because otherwise the folding in along the circular paths does not fold the front face accurately. The known folding in device thus only produces re-folding, and the gable surfaces are also pressed inwardly and are folded inwardly.
The known apparatus is complicated, expensive and prone to malfunctions due to the design of the revolving body and due to the plurality of fold stations.
In addition, the filled and upwardly open packs travel beneath a number of movable parts with the known machine, particularly in the fold station, so that foreign bodies from overlying structural components are able to fall into the open pack. This causes cleaning- and hygiene-related problems.